The University of Mississippi Medical Center proposes to participate as a Clinical Center in NIDDK's Gastroparesis Clinical Research Consortium. Our study team is headed by Thomas Abell, MD, who has a long history of research and clinical experience in the area of gastroparesis. Team members include several leading researchers with whom Dr. Abell has collaborated in the past and who, together, provide a valuable multidisciplinary approach to gastroparesis research. A major strength of this application is the potential study population that UMMC has to offer. We are currently following approximately 1,000 patients with gastroparesis. During the past 41 months, we have evaluated 550 new patients for gastroparesis; thus averaging 160 new patients per year. UMMC strongly supports the establishment of a Clinical Center on its campus. The Medical Center's Vice Chancellor for Health Affairs and the Associate Vice Chancellor for Research have committed to providing the resources necessary to conduct the research of the Consortium. Two protocols have been proposed. The first study is designed to test the hypothesis that gastroparesis patients with one or more overlap syndromes are more likely to respond to a peripheral dopamine blocker than patients without overlap syndromes. Specific aims for this proposal are to: (1) collect and record important information about each of the study participants; (2) document study participants' baseline autonomic status through 24-hour holter monitoring of heart rate variability; (3) provide study participants with a trial of the peripheral dopamine blocker, domperidone; (4) compare the response of study participants with and without overlap syndromes to the phamacologic intervention; and.(5) compare the response of study participants with serologic autoimmune abnormalities to the phamacologic intervention. The second study is designed to test the hypothesis that patients with delayed solid gastric emptying will have better symptom response to temporary gastric electrical stimulation (GES) than those who are non-delayed. Specific aims for this proposal are to: (1) provide training to the Consortium's other clinical centers in the endoscopic placement of temporary GES; (2) conduct a consortium-wide randomized, double-blind clinical trial of temporary GES; (3) compare certain markers at baseline and after the use of temporary GES; (4) determine whether two of the baseline parameters, cutaneous EGG values and mucosal EGG values, can predict response to GES; and (5) based on the results of the study, develop guidelines to better identify those who would most likely benefit from permanent GES.